The present invention relates to generators and, more particularly, to a conductive structural interface for an enclosure for a generator rotor.
In a conventional generator having a rotor and a stator, the rotor is provided with field windings that excite the generator while receiving a current from an exciting current source. The stator is provided with armature windings from which electrical power is output. Typical rotor construction requires that a field winding be assembled bar by bar, into radial slots milled into a rotor forging. Containment of the rotor field windings is typically achieved using rotor wedges, rotor teeth and retaining rings.
It is desirable to replace the bar by bar assembly with a solid rotor having parallel slots milled into a rotor forging. With this structure, the containment components could be replaced with a simplified enclosure.
When composite enclosures are loaded with non-uniform centrifugal radial forces, transverse shear is developed, which may introduce significant inter-laminar shear stresses into the composite enclosure. Additionally, the electrical conductivity of composite enclosures is too low to provide adequate electromagnetic shielding for the field winding. It is thus desirable to provide an interface between the enclosure and the field winding that reduces the shear load on the enclosure, provides electromagnetic shielding of the field winding with good electrical contact with the pole, provides a means of discharging ventilation to the air gap, provides axial stiffness to the structure, and enables axial positioning of individual enclosure rings.